Method of making welds with pieces of coated metal and product thereof.



W. E. WILLIAMS.

METHOD OF MAKING WELDS WITH PIECES OF COATED METAL AND PRODUCT THEREOF. APPLICATION FILED SEPT- 8, 1913.

1 a 1 90,208 Patented July 4, 1916. I

', N TED STATES PATENT names. I

WILLIAM ERALS'IUS WILLIAMS, OF CHICAGO, ILLINOIS.

METHOD OF MAKING WELDSJWITH PIECES F COATED METAL AND PBOID'Q'CT THEREOF.

i To all whom may concern;

Be it known that 1, WILLIAM ERASTUS W1LLIAMs,a citizen of the United States, residing at Chicago, in the county of Cook andState of Illinois,'have invented a new and useful Improvement in -Methods of Making Welds with Pieces of Coated Metal and ProductThereof, of which the follow- ,ing is a specification.

My invention relates especially ,to spot \welding, galvanized iron to black iron, or

galvanizedsheets-or pieces to each other in such manner chiefly valuable in nized or zinc tin and 7 may also be serviceable with other coatings.

My invention is useful in making up iron jivork, such as car doors, elevator doors and many other places.

' It is especially valuable forv outside work,

which is exposed to moisture and notat all x 1 times properly painted.

. Spot welding is not new with galvanized iron but it is diilicult to make successfully with thin sheets for the zinc coating separating theparts to be welded, being a better 3 together conductor of electricity than the iron prevents the generation of the heat at the point of contact where it is most needed, and the weld is. efiected, if at all, by a large Volume of current, or by the heat generated in the iron on either side of the joint, heating by conduction thezinc coating and thus burning it away to permit the iron parts to come and form the weld. \Vhen the weld is thus finally effected, if a good weld is made, ,the parts must be heated to a higher temperature and over a wider area 1 than is needed to weld. uncoatcd metal and this leaves a spot on the outside larger than the weld, where the protecting coating is destroyed-and it is to overcome that my invention relates.

Reference Wlll be had to the accompanythis injury ing drawings in which,-

; g Figure 1 .is a perspective view of some welds made in accordance withmy invention. Fig. 2 is avertical section of the structure of Fig. 1. Fig. 3 shows the parts Specification of Letters Patent.

my invention is Patented July 4, 1916.

I Application filed September 8, 1913. Serial No. 788,642.

I assembled and ready to be welded. Fig. 4

shows a view similar,to Fig. 3. Fig. 5 shows a weld made with two thin sheets. Fig. (5 is a view similar to Fig. 2, showing an alternative construction. Fig. 7 shows a construction similar to that of Fig. 5, and also shows the'positionof the electrodes during welding.

I prefer to use electric welding, wherein the resistance to the current produces the heat as is indicated by F ig. 7 but my invention may be used with gas, or other means.

of heating, if properly handled.

In general, the members to be welded are properly assembled and on one or on each outer face is placed a block which covers and extends on all sides to some distance beyond the area where actual service welding or integralu nion is desired. Heat is then applied centrally to the block or blocks until the central portion and said members are all welded together, each block thus forming a. heavy covering extending beyond that part where the coating has been burned away and itself replacing the lost coating and protecting the denuded part from rapid destructive corrosion.

In the drawings, 1 represents a T-bar to which a thin sheet 2 of coated metal is welded-at points 3, 4 covered by blocks 5, 6, some of which are shown as circular while others appear of square outline. The dotted lines 7 indicate areas within which the coatings on the sheet 2 are destroyed. Although the expedient is not indispensable. the meeting surfaces may be provided with salient contact portions 8, 0 which at the outset both concentrate the heat and hold the members slightly apart so that the coating immediately around them is quickly volatilized and driven out, leaving approximately clean metal, which tends to greater uniformity and perfection in the welding.

Fig. 5 shows relatively thick blocks 11 protecting the spot welds which unite two thin sheets 10, while Fig. 6 shows a thin coated sheet 13 welded to a T-bar and provided with a thin protecting block or sheet 14.

Fig. 7 illustrates uniting two sheets 15 by spot welding, thin protecting blocks 16 being used and the whole being pressed together by electrodes 17- Which heat the parts. as usual.

. The sections to which the coated sheet is welded may be either coated, or plain. Welds are made more easily when the sections are plain, for reasons before stated.

.The protecting blocks may be coated, or plain, and they maybe of iron or other similar-easily corroded metal, or they may be of copper or of corrosion resisting metals.

If the blocks are of copper or similar metal, they should be relatively thin, as'isindicated by 14 and 16,.Figs. 6 and 7, as. slower than the this metal will heat much iron and 'shouldbe thin,.in order to facilitate its getting hot enough to. stick to the Welded point or spot.

If the protecting blocks are' of iron, or similar metal, they should be relatively thick so thick that even if they do corrode at the spot where the weld is made, or over the entire surface, thatdestructive corrosion will consume as much time as amounts to the normal life of the coated sheet, and thus the \voldfed spots will last as long as the sheet itsel When iron or steel is used for the protecting blocks 5, (3 and 11, the welds are more easily made when using relatively thick blocks, as they develop a large volume of heat which by conduction burns oil the coating on sheet 2 more readily than a thin block will do, and thus gets a naked surface between the parts quicker at the points of union than will he arrived at with thin blocks.

What I claim is .1. The method of uniting a thin galvanized iron shect'to another metal member which consists in overlapping said sheet upon said member, placing a metal block upon the overlapping portion of the sheet, driving off the shcets coating under a relatively small central portion only of said block and integrally uniting said portion with the denuded portion of the sheet and the corresponding portion of said member,

by means of welding heat.

2, The method of securing a thin sheet of galvanized iron to another metal member,

- integrally uniting said portion with the corresponding portions of the sheet and momher, by welding heat; whereby the block serves like a rivet head to hold a portion of the'sheet unefiected by heat.

3. The method of securing a galvanized iron sheet to another iron member, which consists in placing the sheet between said member and a metal block, spot Welding the sheet, member and block at a point materially distant from all margins of the block, to hold the margins! portions of the block closely upon portions of the sheet surrounding the welding point leaving the exposed portion of the coating uninjured by the welding.

The combination with an iron member, of a galvanized iron sheet placed thereon,

and a metal block superposed upon the sheetaiid integrally united, by e reietively small central spot Weld, with said sheet and member and pressing around its margin upon a portion of the sheet having its coating uninjured by the weld n whereby the destruction of that poi ii of the sheet immediately surrounding the Welding point would lea ve the sheet stiil securely held.

In witness whereof, I have hereunto suhscribed in}; name on this 1th day of Septemher 1913, in the presence of two subscribing witnesses.

WILHAM ERASTUS ii l-LLL'iHS.

iVitnesses:

JULIUS Jnxsnn, M. JENSEN. 

